Cryptocurrency Café UVa cs4501 Spring 2015 David Evans

1. Class 12: Mostly About Superfish Cryptocurrency Café UVa cs4501 Spring 2015 David Evans Image from http://www.theregister.co.uk/2015/02/22/lenovo_superfish_removal_tool/ (but I think they stole it from Monsters and Aliens)

2. Plan for Today Difficulty Update Project 2: Part 2 Superfish Calamity! (Attacks on Blockchain)

3. Last Class: Profitability (?) of SP20 >> cumulative_income(1) 79.12571644571238 >>> cumulative_income(12) 571.0928818228372 >>> cumulative_income(24) 562.7786595271843 >>> cumulative_income(17) 619.9072133191279

4. https://bitcoinwisdom.com/bitcoin/difficulty

5. Old difficulty: difficulty = 46684376317 # updated 22 Feb 2015 # 44455415962 # from https://blockchain.info/stats, 15 Feb 2015 # this is a very low assumption - over past year, average rate was 0.35 rate_of_difficulty = 0.05 … defcumulative_income(months): income = 0.0 month = 0 while month < months: income += expected_income(month) month += 1 return income >> cumulative_income(1) 79.12571644571238 >>> cumulative_income(12) 571.0928818228372 >>> cumulative_income(17) 619.9072133191279 Note: actual increase since Jan 29: 0.13 New difficulty: >>> cumulative_income(1) 72.41808586293124 >>> cumulative_income(12) 508.6688931963315 >>> cumulative_income(16) 540.5796294385948 >>> cumulative_income(17) 540.5038281854024

6. Old difficulty: difficulty = 46684376317 # updated 22 Feb 2015 # 44455415962 # from https://blockchain.info/stats, 15 Feb 2015 # this is a very low assumption - over past year, average rate was 0.35 rate_of_difficulty = 0.13 … defcumulative_income(months): income = 0.0 month = 0 while month < months: income += expected_income(month) month += 1 return income >> cumulative_income(1) 79.12571644571238 >>> cumulative_income(12) 571.0928818228372 >>> cumulative_income(17) 619.9072133191279 Note: actual increase since Jan 29: 0.13 New difficulty: >>> cumulative_income(1) 72.41808586293124 >>> cumulative_income(12) 508.6688931963315 >>> cumulative_income(16) 540.5796294385948 >>> cumulative_income(17) 540.5038281854024 At 13%: >>> cumulative_income(1) 72.41808586293124 >>> cumulative_income(7) 239.03863987346259 >>> cumulative_income(8) 234.54128929077427

7. from Feb 18 (Class 11):

8. from Feb 18 (Class 11): this morning (Feb 23):

9. PointCoin Difficulty

11. Project 2 Part 2 starts after class today Understand threats to the blockchain Attack the PointCoin network

12. Rules • The blockchain reported by http://blockexplorer.bitcoin-class.org/ is the blockchain that matters (if that node is taken down, the definitive blockchain will be one taken from the course staff nodes) • You may not use any active computing power for mining other than your EC2 nodes • You may not misuse any University resources • You may not do anything that violates Amazon’s acceptable use policy (http://aws.amazon.com/aup/)

14. Opportunities • Collusion is permitted (indeed, encouraged!) • You should have mutual distrust for your classmates (just for this assignment!) • If you join a mining pool, it is encouraged that you (attempt to) deceive the pool operator (or other pools) to gain an advantage • If you operate a mining pool, fine to attempt to cheat pool members

15. Do Something Else! • Posted Project 2 / Part 2 is the default. • I hope some students will do other things! • Alternatives: • Build a PointCoin exchange • Use scripts in interesting ways • Build naming service using PointCoin • … If you have an idea for something different to do, let me know.

16. What Happened with Lenovo?

19. https://www.google.com/#q=chair

20. SSL (Secure Sockets Layer) Client Server Hello KRCA[Server Identity, KUS] Verify Certificate using KUCA Check identity matches URL Generate random K DecryptusingKRS EKUS(K) Secure channel using K Simplified TLS Handshake Protocol

21. SSL (Secure Sockets Layer) Client Server Hello KRCA[Server Identity, KUS] Verify Certificate using KUCA Check identity matches URL Generate random K How did client get KUCA? DecryptusingKRS EKUS(K) Secure channel using K Simplified TLS Handshake Protocol

23. Certificates How does VarySign decide if it should give certificate to requester? VarySign.com petitions.gov, KUPetitions CP= KRVarySign[“petitions.gov”, KUPetitions] TJ CP Verifies using KUVarySign Petitions

24. $399 $1499 for 1 year

28. How could SuperFish insert ads in SSL traffic?

29. Reminder: do not launch DDOS attacks on PointCoin!

30. Internet explorer connects to a web server on port 443 using SSL. The data is encrypted. • Komodia’sSSL hijacker intercepts the communication and redirects it to Komodia’s Redirector. The channel between the SSL hijacker and the Redirector is encrypted. • At this stage, Komodia’s Redirector can shape the traffic, block it, or redirect it to another website. • Communication between the Redirector and the website is encrypted using SSL. • All data received from the website can be again modified and/or blocked. When data manipulation is done, it is forwarded again to Internet explorer. • The browser displays the SSL lock, and the session will not display any “Certificate warnings”. http://www.komodia.com/products/komodias-ssl-decoderdigestor (in archive.org)

31. SSL (Secure Sockets Layer) Client Server Hello KRCA[Server Identity, KUS] Verify Certificate using KUCA Check identity matches URL Generate random K DecryptusingKRS EKUS(K) Secure channel using K Simplified TLS Handshake Protocol

33. Charge Project 2 Part 2: Starts Now Due Thursday 5 March Quiz Wednesday